HTTPClient 调用接口的实例及Bug

今天写了一个通过 httpclient 进行远程调用接口获取 json 并将json 转换成对象保存到mongodb数据库的测试类，错误代码如下：

@Slf4j
@RunWith(SpringRunner.class)
@SpringBootTest
public class HttpClientTest {

    @Autowired
    private JournalInfoService journalInfoService;

    @Test
    public void doGetTestOne() {
        // 获得Http客户端(可以理解为:你得先有一个浏览器;注意:实际上HttpClient与浏览器是不一样的)
        CloseableHttpClient httpClient = HttpClientBuilder.create().build();
        // 创建Get请求
        HttpGet httpGet = new HttpGet("http://www.sciencedb.cn/dataSet/metaData/698");
        // 响应模型
        CloseableHttpResponse response = null;
        try {
            // 由客户端执行(发送)Get请求
            response = httpClient.execute(httpGet);
            // 从响应模型中获取响应实体
            HttpEntity responseEntity = response.getEntity();
            System.out.println("响应状态为:" + response.getStatusLine());
            if (responseEntity != null) {
                System.out.println("响应内容长度为:" + responseEntity.getContentLength());
                System.out.println("响应内容为:" + EntityUtils.toString(responseEntity));
                String s = EntityUtils.toString(responseEntity);
                TestDataSetEn testDataSetEn = JSON.parseObject(s, TestDataSetEn.class);
                TestDataSetZh testDataSetZh = JSON.parseObject(s, TestDataSetZh.class);
                journalInfoService.importEn(testDataSetEn);
                journalInfoService.importZh(testDataSetZh);
            }

        } catch (ClientProtocolException e) {
            e.printStackTrace();
        } catch (ParseException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try {
                // 释放资源
                if (httpClient != null) {
                    httpClient.close();
                }
                if (response != null) {
                    response.close();
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }
}

使用如上的代码报出来以下的异常：

java.io.IOException: Attempted read from closed stream.
    at org.apache.http.impl.io.ChunkedInputStream.read(ChunkedInputStream.java:177)
    at org.apache.http.conn.EofSensorInputStream.read(EofSensorInputStream.java:135)
    at sun.nio.cs.StreamDecoder.readBytes(StreamDecoder.java:284)
    at sun.nio.cs.StreamDecoder.implRead(StreamDecoder.java:326)
    at sun.nio.cs.StreamDecoder.read(StreamDecoder.java:178)
    at java.io.InputStreamReader.read(InputStreamReader.java:184)
    at java.io.Reader.read(Reader.java:140)
    at org.apache.http.util.EntityUtils.toString(EntityUtils.java:227)
    at org.apache.http.util.EntityUtils.toString(EntityUtils.java:308)
    at cn.sciencedb.jpa.HttpClientTest.doGetTestOne(HttpClientTest.java:53)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:50)
    at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
    at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:47)
    at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
    at org.springframework.test.context.junit4.statements.RunBeforeTestExecutionCallbacks.evaluate(RunBeforeTestExecutionCallbacks.java:73)
    at org.springframework.test.context.junit4.statements.RunAfterTestExecutionCallbacks.evaluate(RunAfterTestExecutionCallbacks.java:83)
    at org.springframework.test.context.junit4.statements.RunBeforeTestMethodCallbacks.evaluate(RunBeforeTestMethodCallbacks.java:75)
    at org.springframework.test.context.junit4.statements.RunAfterTestMethodCallbacks.evaluate(RunAfterTestMethodCallbacks.java:86)
    at org.springframework.test.context.junit4.statements.SpringRepeat.evaluate(SpringRepeat.java:84)
    at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325)
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:251)
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:97)
    at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
    at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
    at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
    at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
    at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
    at org.springframework.test.context.junit4.statements.RunBeforeTestClassCallbacks.evaluate(RunBeforeTestClassCallbacks.java:61)
    at org.springframework.test.context.junit4.statements.RunAfterTestClassCallbacks.evaluate(RunAfterTestClassCallbacks.java:70)
    at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.run(SpringJUnit4ClassRunner.java:190)
    at org.junit.runner.JUnitCore.run(JUnitCore.java:137)
    at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:68)
    at com.intellij.rt.execution.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:51)
    at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:242)
    at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:70)

这个异常我个人理解是 EntityUtils.toString(responseEntity); 使用了之后就不能再使用因为链接没有关闭（意思就是在这个测试类中只能使用一次）。所以修改代码如下：只要是把输出 System.out.println("响应内容为:" + EntityUtils.toString(responseEntity)); 的这行代码注释掉就能运行成功。修改代码如下：

@Slf4j
@RunWith(SpringRunner.class)
@SpringBootTest
public class HttpClientTest {

    @Autowired
    private JournalInfoService journalInfoService;

    @Test
    public void doGetTestOne() {
        // 获得Http客户端(可以理解为:你得先有一个浏览器;注意:实际上HttpClient与浏览器是不一样的)
        CloseableHttpClient httpClient = HttpClientBuilder.create().build();
        // 创建Get请求
        HttpGet httpGet = new HttpGet("http://www.sciencedb.cn/dataSet/metaData/698");
        // 响应模型
        CloseableHttpResponse response = null;
        try {
            // 由客户端执行(发送)Get请求
            response = httpClient.execute(httpGet);
            // 从响应模型中获取响应实体
            HttpEntity responseEntity = response.getEntity();
            System.out.println("响应状态为:" + response.getStatusLine());
            if (responseEntity != null) {
                System.out.println("响应内容长度为:" + responseEntity.getContentLength());
//                System.out.println("响应内容为:" + EntityUtils.toString(responseEntity));
                String s = EntityUtils.toString(responseEntity);
                TestDataSetEn testDataSetEn = JSON.parseObject(s, TestDataSetEn.class);
                TestDataSetZh testDataSetZh = JSON.parseObject(s, TestDataSetZh.class);
                journalInfoService.importEn(testDataSetEn);
                journalInfoService.importZh(testDataSetZh);
            }

        } catch (ClientProtocolException e) {
            e.printStackTrace();
        } catch (ParseException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try {
                // 释放资源
                if (httpClient != null) {
                    httpClient.close();
                }
                if (response != null) {
                    response.close();
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }
}

解决问题：
<把输出System.out.println("响应内容为:" + EntityUtils.toString(responseEntity));这行代码注释掉就能正常运行。